Hey guys i bought my evo ix mr about 4 months ago and im starting to detect knock recently. I have read that it could be anything from exhaust noise to a bad knock sensor to even loud cams especially the kelfords which is what the car has.. It seems to only happen when i do a 3rd gear pull but it does not always happen. The check engine light will flash about 4-5 times. I can tell the car is tuned rich and i am having it retuned next week to be safe but i was just wondering what are the major causes of knock and should i be worried with it blinking that many times. Sorry if its a noob question. Also seems worse when its colder outside.

Mods are kelfords 272,injen uicp,licp,3"exhaust with test pipe,act clutch,lightweight flywheel,255walbro,1250cc fic injectors.. Its currently tuned at 18psi.


any help is appreciated.

 

bad/ low octane gas, excessive cylinder pressure, too much timing (ie bad tune). It can be phantom knock, from the cams or the lightened flywheel/clutch combo. Your tuner should be able the check for it. Also, I shouldn't get worse with cold weather. Good luck

 

Thanks for the info. The car was tuned by some shop before i bought it so hopefully after the tune next week it will be better. I just was not sure why it only happens in 3rd gear though.

 

i would stop driving it if I was you ... and take it back asap .. and good luck Sr

 

I wouldn't go that far. But a good way to check is to do a 4th (1:1) gear WOT pull and log. That goes through most of the load range (which encompasses 3rd gear load). If you're getting knock there, you let out. If not, it may be the frequency of the vibrations in 3rd. Also, is the SES blinking fast or slow? Some tuners leave 1-2 counts in the tune (sacrifice for more power). If that's the case, make sure the next person to tune pulls timing there. There's no point in that methodology for a couple hp.

 

It's not my daily so it's okay plus as soon as I notice it I let out. I figure as long as it does not do it ever time I get on it it's not too bad but we will see next week.
I will try the 4th gear today. When it happens the ses sometimes goes super fast but sometimes it slows down. The next tuner has a great reputation so hopefully it will be gone. I have noticed if a Harley is next to me and I slightly get on it,it will blink also so leads me to think its very sensitive aswell..

 

did you get to test drive it before the shop tuned it?

 

Were all of those mods on the car before you purchased it?

 

Car was tuned by the previous owner before I bought it.
Yes all the mods were done by the PO. When I first got it, it would rarely do it but now seems to be more frequent. But only in 3rd

 

i would get tscompusa to tune it. my car did this too,just a crappy tune. then he tuned it and now it doesnt do it anymore,just a butter smooth car now.

 

This...get the tune looked at by a good tuner and your problems will probably disappear.

 

Thanks for the input. I'm hoping it's just the tune so that's why I'm getting it retuned. Car sits in the garage mostly anyway but when I do have fun I don't want to have to think oh crap lol

 

did the 4th gear and not even one knock count.

 

This pretty much points to phantom knock from vibration. That's why in colder weather (less expansion) things rattle more, hence showing the ecu more knock. I had a similar issue where one moment I'd get the knock light in 4th, then couldn't replicate it. Sometimes i would randomly get "knock" under light acceleration 2nd.

I wouldn't be so worried as to not drive it, but I would have it double checked just in case. Good luck

 

Oh okay. Thanks for all the help man. I Will get it retuned and hopefully it will be gone. Thanks again